ABSTRACT
CASRN: 627-20-3; molecular formula: C5H10; FW: 70.13; Merck Index: 12, 7263 Physical state, color, and odor: Clear, colorless, flammable liquid with a disagreeable odor. Melting point (°C): -151.4 (Weast, 1986) Boiling point (°C): 36.94 (Scott and Waddington, 1950) Density (g/cm3): 0.6556 at 20 °C, 0.6504 at 25 °C (Dreisbach, 1959) 0.6614 at 16.50 °C, 0.65152 at 25.00 °C (Curtice et al., 1972) 0.6503 at 20 °C (Dean, 1987) Diffusivity in water (x 10-5 cm2/sec): 0.85 at 20 °C using method of Hayduk and Laudie (1974) Dissociation constant, pKa: >14 (Schwarzenbach et al., 1993) Flash point (°C): -18 (Sax and Lewis, 1987) Entropy of fusion (cal/mol⋅K): 13.96 (Chao et al., 1983; Todd et al., 1947) Heat of fusion (kcal/mol): 1.700 (Chao et al., 1983; Todd et al., 1947) Henry’s law constant (atm⋅m3/mol): 0.225 at 25 °C (approximate - calculated from experimentally determined water solubility and vapor pressure values) Ionization potential (eV): 9.01 (Lias, 1998) 9.11 (Collin and Lossing, 1959) Soil organic carbon/water partition coefficient, log Koc: Unavailable because experimental methods for estimation of this parameter for aliphatic hydrocarbons are lacking in the documented literature Octanol/water partition coefficient, log Kow: 2.15 using method of Hansch et al. (1968)
Soluble in alcohol, benzene, and ether (Weast, 1986) Solubility in water: 203 mg/kg at 25 °C (shake flask-GC, McAuliffe, 1966) Vapor density: 2.87 g/L at 25 °C, 2.42 (air = 1) Vapor pressure (mmHg): 494.6 at 25 °C (Wilhoit and Zwolinski, 1971) 289.12 at 11.486 °C, 355.21 at 16.494 °C, 433.50 at 21.541 °C, 525.81 at 26.633 °C, 633.94 at
31.766 °C (ebulliometry, Scott and Waddington, 1950) Environmental fate: Photolytic. The rate constant for the reaction of cis-2-pentene and OH radicals in the atmosphere at 300 K is 3.9 x 10-13 cm3/molecule⋅sec (Hendry and Kenley, 1979). Atkinson (1990) reported a rate constant of 6.50 x 10-11 cm3/molecule⋅sec for the same reaction. Chemical/Physical. Complete combustion in air yields carbon dioxide and water. Source: Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle-phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The gas-phase emission rate of cis-2-pentene was 10.4 mg/kg of pine burned. Emission rates of cis-2-pentene were not measured during the combustion of oak and eucalyptus. California Phase II reformulated gasoline contained cis-2-pentene at a concentration of 2.29 g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 0.44 and 42.3 mg/km, respectively (Schauer et al., 2002). Uses: Polymerization inhibitor; organic synthesis.
